The three monotheistic religions, similarities and differences. The lecture is based on what religion is at all. Is it a matter of identity, or is it only something you choose as a kind of item? There are different attitudes to them and we will first look at them. In any case, we must recognize that there is more than ever to know something about the three religions, Judaism, Christianity and Islam - the three great monotheistic religions, their community and their differences: how and why.